Shearing sound from gearbox at certain RPM

[psneddon]

Hi,

I've noticed that when I am in 2nd gear and I am accelerating thought a certain RPM (20mph) there is a kind of shearing noise heard, sort of like someone shearing a knife across a cheese grater or something and lasts about as long.

The only place I have really noticed this notice is when I have my window down and am going up a slope with a wall to the side to reflect the sound so its not that loud.


I also notice it in 1st gear too. It also only seems to happen on slopes and goes away after I've been driving for a while.

Just wondered if anyone thinks this is anything to worry about? Could it be the syncro? Is it normal?

Paul

[lakersfan1]

Could be any number of things. Gears, bearings, axles, etc. You should try to find out which side of the car it's eminating from first, then look at that half of the engine bay first.

[psneddon]

It seems like it is coming from under the car, probably the gearbox. I have just tested it and it does go away when after I've been driving about for a few minutes. Could it be I need to use a different gearbox oil? I suppose its one of the easiest things to try.

[perhapsadingo8yerbaby]

Just to be sure of the source, park near a wall & have someone rev the rpms up in neutral before the motor warms up. See if you can hear the sound. If not, could still be a tranny noise but I've heard sounds like that come from a worn alternator, heat shields around the exhaust etc. and ya just wanna isolate it a bit more before assuming too much. These things can be tough to isolate from inside the car while driving. My .02

[greenstorm]

its a rusty exhaust usually. Ive seen this many times. It happens at either one certain rpm (or a couple) and it doesnt do it when not moving (because engine isnt under full load i think)

[psneddon]

Not a peep from the car when revving in neutral. Sounds totally fine. Also sound definetly disappears after 5 mins of driving.

Paul

[monty73741]

i have heard that the sound is the clutch throwout bearing

jason

[psneddon]

Anything to do with the clutch sounds bad I'm really hopping an oil change will sort it since it seems to go away after the car has been runninga while. I really does sound like a gearbox sound though.

Paul

[psneddon]

Another thing that may or may not be related. Sometimes when I first start my car in the morning when it has been wet and cold and move off it feels like the rear axel is sticking and seems to cluck free. I put this down to the wax rust protection I recently sprayed on. Mind you it hasnt happened in a while.

[psneddon]

Well its not the oil level as its full. Going to change it tomorrow for some Castrol Syntrax.